Thiophosphoric acid esters and their production



Unite THIOPHOSPHORIC ACID ESTERS AND THEIR" PRODUCTION Statfis Gerhard Schrader, Opladen, Germany, assignor to Farben- I fabriken Bayer .Aktiengesellschaft, Leverkusen, many, a corporation of Germany No Drawing. Application August 28, 1956 t Serial No. 606,554

Claims priority, application Germany September 7, 1955 7 Claims. (Cl. 260461) Ger- Thiophosphoric acid ester derivatives have become very Y important pesticides during the recent years, and a con- 2,864,849 aPa'ten'ted Dec. 16, 1958 lce tion typically include water or H1611 organic solvents such as liquid'hydrocarbons, alcohols, ketones, nitriles,

etc. and more specifically benzene,- toluene, hexane, methanol," ethanol, isopropanol, acetone, methyl-ethyl ketone, acetonitrile, etc. Compatible mixtures of t-hese solvents may, of course, be utilized. The reaction,- how-i ever, may also be carried out by dissolving the haloa'ioyl urethanes and the free 0,0-diester-thiophosphoric acid in an inert'organic solvent, especially in lower aliphatic alcohols suchas methanol orethanol and then by "adding organicor preferably inorganic basic substances 'suclifa's sodium hydroxide, sodium carbonate, sodium or potay sium alcoholate,-Ztrimethylamine, etc.--'to said solutions, thereby splitting offithe halogen from the 'haloa'cyl urethanes'and forming the desired inventive new thiophosphoric acid esters.

against aphids.

siderable amount of work has been done incthis field.

Nevertheless, there are still needed moreeffective and less toxic compounds, especially such compounds which excel additionally in their systemic action on the plant Therefore, it is a principal object of .the present invention to provide a new and useful class of thiophosp horicacid esters. Another object is to providea'method for preparing these compounds; stillfurther objects will become apparent as the following description proceeds.

In accordance with the invention, it has been found that compounds of the :above formula'may Else-obtained 'by reacting salts of O,-O-dialkyl-thiol-(or thionoA-hiol) phosphoric acids with hHIO-aCYI IlJI'E ihEIIES. This reaction may typically be shown by the following equation:

using the ammonium salt of 0,0-diethyl-dithiophosphoric acid and chloroacetyl-urethane as starting materials.

Instead of salts at the diethyl-dithiophosphoric acid ester, however, also salts of other esters, such as of the dimethyl, dipropyl, dibutyl, diamyl, diphenyl or dicyclohexylester may be used. Also other alkali metal salts such as sodium or potassium salt are suitable reactants in this reaction. Moreover, the thiol-esters may be used instead of thiono-thiol esters. Instead of chloro-acetylurethane also other halo-acyl compounds such as bromopropionyl, urethane may be used. Also other esters of the urethane series (i. eother amino-carbonic-acid-esters) such as the methyl, propyl, butyl, etc. esters may be used according to the present invention.

The reaction generally may be carried out at temperatures from about 0 to about 150 C. especially in a range from about 30 to about 90 C., preferably with the thiol phosphoric acid ester reactant in salt form. If saltsof thiolor thiono-thiol-phosphoric acid0,0-diesters are used, the reaction preferably is carried out by adding a solution of this salt to a solution of the halo-acylurethane. Solvents which are suitable for the condensa- The compounds of the present invention exhibit very goodbiological activity, while having" a remarkable low toxicity against-.mammals Y 'IT-heym'ay widely be used as insecticides against e. g. flies, mites and especially The application proceds'in the usual way .forIhe use-of- ,phosphor-insecticides, i. e. preferably the-cornpoundsmay be -dissolve'd.or'diluted with: liquid or solidrcarriers, such as water, alcohols,liquidhydrocarbons, ketones of chalk talks,.bentonite,jetc. .Thesecompo;

sitions or the new compounds maybe. sprayed or dus'ted e. .gwas. aerosols, or otherwise -broughtfinl -contact with pests or,.plants whereon the pests are living, ,norrnallyin concentrations from about-0.0001 to 1.0%. i I Theffollowingexamplesaregiven byway of illustrating this invention, :without, however, restricting it thereto Example] 'GJHSQ i 168 g. of chloroacetyl-urethane and g. of 0,0-diethylthiolthionophosphoric. acid are dissolved in 1100 ccm. of ethanol.- -Ataternperatureof 45 C. there are added 1000 ccm. of an n/l sodium hydroxide solution.

After the addition has been completed the resulting reaction mixtureis filteredotf from, 'somexini puritieswand thenydiluted with 1200; ccm. of; water. The reaction product thereby precipitates in crystalline: form. After filtering ofli and drying there are; obtainedZlO :g-.'. (170% of the theory) of the melting point 73 C.

If instead of chloroacetylurethane the corresponding amount of a-chloropropionylurethane is used there is ob tained the ester of the formula:

' olnso s 0 \H II II P--SCHCNH-OO 0:11

olrno H3 Example 2 iCaHoO S O 0 \II II II PSOH-zCNHCOO2H of the theory) of the melting point 167 g. of chloroacetyl-urethaneare dissolved in'350 ccm. of methanol. While stirring there are added 180 g. of the sodium salt of O,O-dimethyl thiol-thiono-phosphoricacid, dissolved in 300 ccrn. of water, at a tempera- ,ture of about 80 C. After stirring for a further hour at this temperature, the reaction mixture is diluted with 500 ccm. of cold water; The reaction product'precipitates as an oil which is taken up in 400 ccm. of benzene.- The benzene layer is washed twice with 25 ccm. of water, dried over sodium sulfate and the solvent then is distilled off. The oily residue slowly crystallizes and then melts at 45 C. There are obtained 160 g. of colorless crystals.

V Example 4 03.0 o o o it i -s-om- -Nn-g-oola CIHIO 76 gQof the ammonium saltof 0,0-diethyl-thiol-phosphoric acid are dissolved in 200 ccm. of methylethylketone. At a temperature of about 75 C. there are added 66 g. of chloroacetylurethane, dissolved in 200 com. of methylethyl-ketone. The mixture is kept at this temperature for further 1 /2 hours, then cooled and filtered ofi from precipitated ammonium chloride. After evaporating thesolvent the residue is taken up in chloroform. This solution is washed with water and finally driedfover sodium sulfate. After distilling off the solvent there are obtained 75 g. of the crude ester (83% of the theory). The ester slowly crystallizes and then shows the melting point of 44 C. r

I claim:

1. A phosphoric acid ester of the general formula in which R stands for a lower alkyl radical, X stands for a member selected from thegroup consisting of oxygen and sulfur, Y stands for lower alkylene and R is a lower alkoxy radical.

2. A method of preparing a phosphoric acid ester of the general formula R r l in which R stands for a lower alkyl radical, X stands for a member selected from the group consisting of oxygen and sulfur, Y stands for lower alkylene and R is a lower alkoxy radical, which comprises reacting a member selected from the group consisting of the ammonium salt and alkali metal salt of the corresponding 0,0-dialkyl ester of a thiol-phosphoric acid and a haloacylurethane in an inert solvent and recoveringthe product formed.

3. The phosphoric acid ester of the formula:

01H50 s o 0 \H H ll PS-CH2C-NH OCH5 CaHs 4. The phosphoric acid ester of the formula:

\fi I u P-S-CHCLNHC-OC:H5

C3H50 CH:

5. The phosphoric acid ester of the formula:

/OHO s V O O \H II II PSCH:C-NHOO CzH Cg: /CH0 6. The phosphoric acid ester of the formula:

cmo

PSCHr-CNHCOC:H; arm l ll 7. The phosphoric acid ester of the formula:

s; t e P--SCHr-C-NH( JO C1Hs GdEhO References Cited in the file of this patent UNITED STATES PATENTS 2,494,126 Hoegberg Ian. 10, 1950 

1. A PHOSPHORIC ACID ESTER OF THE GENERAL FORMULA 